There’s nothing built-in to serve static files, but it would be relatively easy to add something.
Another option is to put the static pages in a “book” in the database – that keeps the system more self contained. But it means using Suneido’s book editor whereas you might want to use an external HTML editor.
Currently the “routing” with HtmlMap is quite basic. You would need to do something like add a “file” entry and map it to a function that reads external files, but then the url would have to be /file/…
I think the stdlib HtmlMap had a “Res” entry that mapped to GetBookRes
The other option would be to modify HttpServer e.g. so if the path wasn’t found it would look in some directory.
Hope that helps.